Malicious PDF — malware analysis report

Static analysis result for SHA-256 13c51ae5e2e972cf…

MALICIOUS

PDF

84.4 KB Created: 2021-06-26 21:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 940db34435641167964a0a3d8a70b857 SHA-1: 3dab34526d6a0edb2bcf17d019c24249b29ad5f8 SHA-256: 13c51ae5e2e972cf4c132fa63ddd95a31006fbecac03e65d4773b07d3f5b7946
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites, likely intended to lure users into downloading further malicious content or visiting phishing pages. The presence of a download button lure reinforces this phishing pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160af95791ec42---rinegiju.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/d074c5fb1c1d50533af1dd85306558cd/wonunajetufej.pdf
    • https://mfdesign.hu/files/file/67613223104.pdf
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c63fe6a094f---boxugofomuparejujenifubu.pdf
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b9b8ad441a7---tojegujupozej.pdf
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/def33878531ac7bd41279592c02e12ec/97320623648.pdf
    • https://pensiuneavlasin.ro/wp-content/plugins/super-forms/uploads/php/files/h56038r0s3btdnoqbdvr1vvu79/24656641992.pdf
    • https://eletvital.hu/uploads/files/31033875096.pdf
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/2c024be5c3d57f96b8cd7f4cdf304cc9/76402302465.pdf
    • http://sshs61.com/clients/6/60/60e739d5a8cf4a6710e4f064fd99417d/File/81521209020.pdf
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/a7cab12f228eeb7abbd1a4c4644f971d/21939433501.pdf
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/16083d7753e734---bunimumekiz.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160728c6bd26e8---kufanofenewiruju.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160893c5e32cc1---jazunuwomezupijudu.pdf
    • http://ztkammer.at/uploads/file/51930773373.pdf
    • https://fotobolfestmeny.hu/mvc/userfiles/file/11492748700.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16077f2cc801d9---95928898438.pdf
    • https://sabagdasarov.ru/upload/file/81874125428.pdf
    • http://wsm.hk/images/uploadfiles/file/82726297463.pdf
    • http://shinies.ru/img/lib/file/wufalivosibajugalex.pdf
    • http://melly-incendie.fr/img_db/5735498417.pdf
    • http://bawaconstructions.com/editorData/file/69790769426.pdf
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8f03c4134---8759959373.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+edit+a+fillable+form+in+word
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e96e.bin
59b521e558495f5a5b73277fd5609c64ee240c1ccf2c917b0cab3d5020f57a3d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE96E 16440 bytes
font_01_sfnt_off00011434.bin
344322d8fccd8b46777d937e7c8744680675242baee639c9ba27b7bd3d5480d0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11434 10564 bytes
font_02_sfnt_off00012c3d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C3D 16792 bytes